Portable devices that allow an operator to collect and review data have been developed for a wide variety of applications and have become highly popular as a cost effective mechanism by which to perform a number of essential business activities such as inventory data collection and communication functions such as automatic product identification and inventory review. While the specific features of such devices vary dependent upon the application, nearly all are designed for and require hand-held use. And in the vast majority of applications, the traditional data input source--the keyboard--is impractical or impossible to use. Consequently, a class of portable computing devices has been established that relies on a compact pointer such as a pen, stylus or finger to enter data through a proximity or touch sensitive display. Virtually all these devices, commonly referred to as pen or pen-based computers, furnish a microprocessor based, tablet-sized control unit that is cradled with one hand and operated with the other hand. A very few pen computers, such as the Model PPT4100 made by Symbol Technologies, Inc. of Bohemia, N.Y., and the Model Pen*Key made by Norand Corporation of Cedar Rapids, Iowa, provide for the optional attachment of an optical (such as laser or CCD) or electromagnetic scanner for automatic interrogation and identification of items on which suitable, corresponding optical or electromagnetic identifiers such as tags or bar-code labels have been placed.
The majority of the hand-held devices heretofore designed to permit data collection and communication have either integrated all components required for the functionality demanded in a given application into a single package, or have permanently joined a plurality of separate modules (e.g., power, microprocessor control and scanner) in a single package. For example, hand-held data collection terminals with integral scanners are disclosed in U.S. Pat. Nos. Des. 325,574 and 5,144,120. Some similar devices also include a pistol grip handle to reduce fatigue when used to scan over longer periods of time, such as that shown in U.S. Pat. No. Des. 320,013 and the Model PTC-960 from Telxon Corporation of Fairlawn, Ohio. U.S. Pat. No. 5,059,778 presents a portable data scanner apparatus that fixedly joins a scanner module, a data module and a power module into a single, self-contained unit having a pistol grip handle.
While integrating all required components for a given application into a single unit may allow less costly manufacture, the inherently limited functionality and inflexibility of integrated units frequently may result in higher ultimate costs to the purchaser/operator with multifunctional applications or with needs changing over time. Moreover, where efforts are made to address multiple applications in a single unit having fixed components, compromises must be or are made that reduce specific application optimization.
One increasingly common approach to overcoming the limited flexibility and often ultimately higher costs of a fixed application device has been to manufacture distinct component functionality in separate modules which may be attached to a base unit. Two more recent examples of this approach may be found in the 1000 Series Modular RF Terminals sold by Norand Corporation of Cedar Rapids, Iowa, and the OmniWand commercially available from Videx, Inc. of Corvallis, Oreg. The Norand 1000 Series allows attachment of a single backpack selected from a variety of backpacks having different combinations of features. The Videx OmniWand allows attachment of a single module selected from a variety of modules having a single function within each module.
In U.S. Pat. Nos. 4,621,189 (invented by me), and 4,983,818 hand-held data acquisition terminals are shown having a keyboard for manual data input and including a single connector for releasable engagement with a separate laser scanner module, allowing operation as a manual data input terminal or scanner. When the scanner module is attached and operating, one hand of the operator holds the terminal and aims the scanner beam while the operator's other hand presses a keyboard button to actuate scanned data acquisition. The connector described in my U.S. Pat. No. 4,621,189 is symmetrical and includes two mirror image rows of contacts so that the scanner module may be attached with the scan beam directed to either the right or left of the terminal, allowing the operator to hold the terminal with either the right or left hand, and operate the keyboard with the other hand.
Unfortunately, these data collection terminals still suffer from deleterious limitations. Single module attachments skew the weight distribution of the hand-held device, making it unbalanced, uncomfortable and difficult to hold and operate for extended periods of time, a problem that escalates as the features and weight of the modular attachment increases and is further exasperated by the need for two-handed operation. Also, because only one module is attachable at a time, more frequent module swaps are necessary in certain changing data collection applications. Perhaps most significantly, no hand-held device with replaceable modules permits one-hand operation in both right- and left-handed configurations, particularly with the simultaneous connection of two modules.